July 28, 2021 Applied Measurements Blogs Comments Off

Monitoring and regulating temperature is a fundamental part of everyday life. Temperature sensors help monitor and control equipment and machinery as well as the environment in homes, schools, hospitals, factories and more.

Advanced temperature sensors have become highly accurate, stable and reliable devices that utilise a range of technologies and offer a wide range of features that allow them to be used in a variety of applications and environments.

When you’re in the market for a temperature sensor, there are a variety of factors to consider. It’s important to find a high-quality temperature sensor to get the most accurate readings and get more bang for your buck – inferior temperature sensors could wind up being detrimental to your equipment. But how do you know what to look for? To help you evaluate temperature sensors and spot an inferior version, we’ve compiled the 10 most essential considerations.

Accuracy

Above all, it is crucial to make sure that your temperature sensor is accurate. Inferior temperature sensors will have a smaller range in which they are accurate over, which limits the application usage. Always review a data sheet to determine the accuracy over the whole range. In some cases, they may be accurate for a short time but will tend to drift very quickly due to design quality.

Temperature range

Determine what the minimum and maximum operating temperatures will be. Always view a data sheet to verify whether your application fits into the range of the sensor you are intending to use. A common mistake is not matching the right sensor to the right application. Do not use a common RTD in specialised applications. TE have a wide range of application specific RTD elements to suit applications that are cryogenic in nature (-200 deg C) right up to furnace reference probes (up to 1000 deg C).

Material being measured

Before purchasing a temperature sensor, consider the application and what is being measured and whether there are any operating conditions that could adversely affect the sensor. For example, is it a gas or a liquid? This may change the type of sensor you need. If it is measuring a liquid, it will need to be waterproof. If the sensor is being used for cooking, it will need to be stainless steel to suit food-grade applications. These are important details to work out – getting the wrong temperature sensor could have detrimental consequences.

Repeatability

High-quality temperature sensors have a superior level of repeatability, meaning you can use them at extreme temperatures and trust that they will continue to give accurate readings. Sometimes once a low-grade sensor has been used at a high temperature, the sensor may drift at ice point and won’t give you accurate readings from then on. Applications that produce fast moving temperature changes will have a negative impact on an inferior sensor.

Stability

It’s important to invest in a high-quality sensor that will not fluctuate in resistance at the ambient temperature of the environment. Inferior sensors have a tendency to do this, which throws off the accuracy of readings and ability to maintain and stabilise the temperature. The material a sensor is made from can play a big part in its stability – we recommend a platinum RTD for this reason. RTD sensors are renowned for their superior stability over time.

Element size

The TE RTD element range offers a wide range of element sizes to suit a wide array of applications. From small elements for fast response applications to bigger elements to suit more industrial applications. Here at Applied Measurement, we will have the right element to suit your application.

Readings are fluctuating in process but stable when off

If the temperature readings are fluctuating in process but are stable when the equipment is turned off, it’s possible that your element is suffering from induced voltages or errors cause by vibration. This is a very common result in using inferior RTD’s in an industrial application

How long the sensor has been in use

Thermal aging refers to long-term, irreversible changes in the structure, composition and morphology of materials exposed to temperatures that they are typically likely to encounter in service. In a temperature sensor, thermal ageing will introduce drift and inaccuracy. A lower quality sensor will experience this process faster than a high-quality sensor will. Investing in a superior sensor will extend the lifespan of your equipment and ensure that you are getting accurate results over a longer period of time.

Consistent and stable incorrect readings

Using the incorrect sensor in the wrong application can introduce errors. If it’s an application that requires long cable lengths, the length of the connecting leads may introduce errors. Our TE sensors have the option of introducing a temperature transmitter for applications where this may be a problem. Introducing a temperature transmitter will alleviate errors introduced by long cable runs.

Available depth immersion in the application

The available depth immersion in the application will determine the diameter and length you need to look for in a sensor. As a general rule of thumb, the sensor stem length should be 20 times the sensor diameter. If this is miscalculated, it will likely result in inaccurate measurements, which will compromise the workability of the equipment.

Speak with the sensor experts

As experienced measurement equipment suppliers since 1976, our sensor solutions at Applied Measurement Australia are unprecedented and have experience in all forms of industry such as Defence, Oil and Gas, Transport, R&D, Maritime, Manufacturing, Process and Control and many more.

If you want to talk to someone about sensor solutions, contact us to discuss your requirements or application, we are always happy to help!

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